Self-contained underwater breathing apparatus (scuba)

ABSTRACT

An emergency self-contained underwater breathing apparatus (SCUBA) for supplementing a diver&#39;&#39;s normal gas supply system and adapted to be switched on in response to failure of the gas feed from the normal system. This emergency unit comprises an auxiliary source of gas connected through a normally closed outlet valve to a through-flow storage provided with the inhalation and exhalation conduits extending to the diver&#39;&#39;s helmet. On failure of the gas feed from the normal system, the outlet valve of the auxiliary source of gas will open causing the contents of gas under pressure in said source to be emptied into said through-flow storage, thereby forming a closed breathing circuit comprising the through-flow storage, the inhalation and exhalation conduits and the diver&#39;&#39;s helmet. The inhalation conduit has a gas purifier inserted in it.

United States Patent [191 Almqvist et a1.

[ 1 June 28, 1974 SELF-CONTAINED UNDERWATER BREATHING APPARATUS (SCUBA)[75] Inventors: Hans Olof Almqvist, Lidingo; lmre Botos, Bromma, both ofSweden AGA Aktiebolag, Lindingo, Sweden June 15, 1972 Assignee:

Filed:

Appl. No.:

[30] Foreign Application Priority Data June 22, 1971 Sweden 8120/71 US.Cl. l28/l42.2 Int. Cl A62b 7/04 Field of Search. 128/1422, 142, 142.4,128/1426, 145, 146.3, 146.4, 146.5, 211,

References Cited UNITED STATES PATENTS 5/1935 Davis 128/191 R 11/1949Bedini 128/142 l/l962 Medovick 128/142 3,068,864 12/1962 Tietze 137/63 R3,433,222 3/1969 Pinto 128/1422 FOREIGN PATENTS OR APPLICATlONS1,193,522 6/1970 Great Britain 128/188 r550 FROM sxmrmt- SQURCE 3rEELLOWS 9/1964 Great Britain 9/1966 Germany Primary Examiner-Richard A.Gaudet Assistant Examiner-Henry .1. Recla Attorney, Agent, orFirm-Larson, Taylor and Hinds [57] ABSTRACT An emergency self-containedunderwater breathing apparatus (SCUBA) for supplementing a divers normalgas supply system and adapted to be switched on in response to failureof the gas feed from the normal system. This emergency unit comprises anauxiliary source of gas connected through a normally closed outlet valveto a through-flow storage provided with the inhalation and exhalationconduits extending to the divers helmet. On failure of the gas feed fromthe normal system, the outlet valve of the auxiliary source of gas willopen causing the contents of gas under pressure in said source to beemptied into said through-flow storage, thereby forming a closedbreathing circuit comprising the through-flow storage, the inhalationand exhalation conduits and the divers helmet. The inhalation conduithas a gas purifier inserted in it.

7 Claims, 4 Drawing Figures val 2 1 TRIPP/N6 1 MEMBER RETURN 7'0EXTERNAL SOURCE SELF-CONTAINED UNDERWATER BREATHING APPARATUS (SCUBA)The present invention relates to a divers breathing apparatus includinga helmet and comprising an auxiliary source of gas which, through avalve, can be connected to the divers inhalation conduit on the divershelmet.

Prior-art breathing apparatuses of this kind usually employ anopen-circuit system in which the exhalation gas is allowed to dischargefreely into the ambient water. Such units, therefore, require relativelylarge, and thus heavy, auxiliary gas sources to afford for the diver,after switching on the emergency unit, sufficient time to get back tohis base. For deep-diving purposes these units are impractical anduneconomical in use, since the breathing gas employed in this casecontains the expensive rare-gas helium which thus will get lost.

One object of the present invention, therefore, resides in the provisionof a less bulky and light-weight emergency breathing apparatus havingsufficient capacity to afford for the diver sufficient time to get backto his base or to be rescued by another diver.

A further object is the provision of an emergency breathing apparatus ofthe kind stated which will enable a maximum of utilization and recoveryof the limited quantity of breathing gas available.

. These objects are attained by the breathing apparatus beingcharacterized in that said valve normally closing off the auxiliarysource of gas is connected into a con-- duit extending from theauxiliary source of gas to a through-flow storage which is connected tothe divers helmet through inhalation and exhalation conduits,respectively, in such a way that, upon failure of the normal supply ofbreathing gas, said through-flowstorage is arranged to be filled withgas; from said auxiliary source of gas which is arranged to dischargethrough the through-flow storage in response to the opening of saidvalve, thereby closing a breathing circuit which includes a gas purifierinserted in the inhalation conduit.

By the breathing apparatus improved in accordance with the invention,the diver will dispose of an easily carriable emergency breathing unit,since the unit need only consist of a small gas container which willonly contain a sufficient quantity of gas under pressure to fill thethrough-flow storage space.

It has been found possible without any danger for the divers health tosupply a breathing gas mixture, the oxygen partial pressure of which ispermitted, for a short period of time, to exceed an average oxygenpartial pressure value of 1.5 atm. absolute pressure.

Divers are normally supplied with breathing gas from a gas supply systemconnected to the inhalation and exhalation conduits, respectively, onthe divers helmet. Such gas supply systems usually comprise athroughflow storage space. Where gas supply systems of this kind are tobe supplemented with the emergency breathing. apparatus according to theinvention, the through-flow storage space could suitably be arranged incommon to the normal gas supply system and the emergency breathing unit,in which case this unit is arranged to be switched into operation bymanually operable valves. This involves the advantage that the diversbuoyance will not change appreciably when the emergency unit is switchedon.

By designing the through-flow storage space in the form of a bellows,one will obtain an advantageous regulator for the breathing-gas pressurein dependence on the momentary depth level of the diver.

Where the through-flow storage is designed as a bellows, a particularlysuitable constructional form of the emergency source of breathinggas'may be employed, in that the latter may then be constituted by acollapsible container disposed within the bellows. In this way aflexible oxygen storage will be obtained which will vary in capacityaccording to the diving depth. Since the surrounding bellows willnormally be supplied with gas from the normal gas supply system, thefeed from which is dependent on the divers momentary diving depth, thecollapsible container will control the gas quantity fed into thebellows. When switching on the emergency source of gas, i.e., thecollapsible container, the space confined within the collapsiblecontainer will be communicated with the space existing between the wallof the bellows and the collapsible container.

In diving equipments where the emergency breathing apparatus accordingto the invention can be used, it is of advantage in certain cases torelease the diver completely from the normal gas supply system when theemergency breathing apparatus is switched on. For this purpose, it hasbeen found suitable to cause a disconnecting device to separate thediver-carried breathing apparatus from the normal gas supply system inresponse to the divers carrying out the emergency-unit switching-onoperation. In order to prevent wateringress both into the diver-carriedunit and into the normal gas supply system, said disconnecting devicecomprises two oppositely connected non-return valves inserted in eachconnecting conduit from the normal gas supply system and adapted to beactivated in response to the disconnecting operation.

The action of switching on the emergency breathing apparatus accordingto the invention must be carried out quickly and without any resistance,since when taking such action the diver will often be in a situation ofdistress. Thus, it is a desideratum that any coupling operations whichwill have to be carried out to cause perfect functioning of theconnecting-up operation can be effected by one single hand-movement.This has been attained according to the invention by causing the manualdisconnection control member by means of a lever, to actuate thedisconnecting devices and a multifunctional valve device fordisconnecting and interconnecting the various conduits.

The emergency breathing apparatus will be described more specificallyhereinafter with reference to the accompanying drawings, in which:

FIG. 1 illustrates a preferred embodiment of the emergency breathingapparatus according to the invention;

FIG. 2 shows the emergency breathing apparatus of FIG. 1 as connected toan external gas supply system which is connected to the divers breathingequipment;

FIG. 3 illustrates a modification of the apparatus shown in FIG. 2; and

FIG. 4 is an elementary diagram illustrating a practical realization ofthe operation of connecting up the emergency breathing apparatusaccording to the invention.

Referring to the drawings more specifically, FIG. 1 illustrates theprinciples basic of the breathing appara- Although, as illustrated inFIG. 1, the breathing apparatus or unit may be employed as a completelyselfcontained breathing gas system, its intended primary purpose,however, is to be utilized for supplementing another gas supply systemadapted normally to supply breathing gas to the diver. Thus, in FIG. 2the breathing apparatus is shown connected to an external gas supplysystem by a supply or feed conduit 3 and a return conduit 4. In thiscase, the bellows 1 is common to the external gas supply system 3, 4 andthe emergency breathing unit. The emergency breathing unit, similarly tothat described in connection with FIG. 1, comprises an auxiliary sourceof gas 5 connected to the bellows 1 through a valve 6, as well as a gaspurifier 9. This gas purifier 9 is inserted into a branch conduit 10which can be connected between the exhalation conduit 8 and bellows l byactuating a valve 11. The breathing equipment of FIG. 2 furthercomprises disconnecting devices 13, 14 for separating the external gassupply system 3, 4 upon taking the emergency unit into use. Thesedisconnectors 13, 14 as well as the valves 6, 11 are operable by atripping member 12.

The emergency breathing unit is intended to be employable within arelatively large range of depths, such as between 30 and 230 meters, forexample. When carrying out such diving missions, the diver usually hasavailable a diving base or station disposed at a certain depth level andcarrying said external gas supply system 3, 4. Depending on the actualdepth level of the diving station, it is necessary to ensure that theauxiliary gas source 5 is filled with a correspondingly composed gasmixture, being, for instance, pure oxygen, oxygenhelium or the like. Thecapacity of the breathing apparatus or unit must be sufficient to affordfor the diver a time of respite enough long, about 10 minutes, to enablehim to return to the diving base, from which the diver can move away toa limited extent. It has furthermore been found that, in an emergencysituation, the diver may be estimated to consume about 2 liters ofoxygen per minute and to exhale about 1.7 liters carbon dioxide perminute. Departing from these values, it results that the emergencybreathing unit must be capable of supplying liters of oxygen and ofcollecting 17 liters of carbon dioxide.

If the utilization of the emergency breathing unit is limited to aperiod of time of only 10 minutes, it has been found possible, withoutendangering the divers health, at the beginning of said period tosupplymetered gas at an oxygen partial pressure of about 2 atm. absolutepressure, which is then reduced progressively as the oxygen is consumed.It is essential that the average oxygen pressure cannot exceed 1.5 atm.abs. pressure during a minor portion of the time period, prefera- 6 Withthe data thus specified, the following oxygen concentrations would beproper for the gas contained in the bellows 1 forming part of theemergency breathing unit:

Diving depth (meters) Oxygen (7:)

Thus, when predetermining the contents of the auxiliary gas source 5, itis necessary to take into account the depth level of the diving base orstation, so that the gas mixture will be of the proper composition andso that the oxygen partial pressure will not exceed its allowablemaximum value. This allowable maximum value of the oxygen partialpressure is determined by the maximum diving depth attainable by thediver from the diving base or station when the latter is disposed at acertain depth level. The following table specifies the oxygen contentrequired to be supplied by the auxiliary gas source 5 at thee beginningof the period of utilization of the emergency breathing apparatus whenthe base or station is disposed at the depths specified and provided themaximum value of the diving depth is 30 meters below the depth level ofsaid base or station.

Base depth level Thus, the auxiliary source of gas 5 will have to befilled with a gas mixture containing 14 percent of oxygen when thediving base or station is at a depth level of meters.

FIG. 3 illustrates a modified emergency breathing apparatus or unitaccording to the invention. It corresponds largely to the unitillustrated in FIG. 2, but is provided with an auxiliary source of gas 5disposed within the bellows 1. This auxiliary gas source 5 in thepresent case, is constituted by a collapsible container 15, the interiorof which can be communicated with the space confined by the bellows l bya valve 17 inserted into a conduit 16. The valve 17 also is operable bythe tripping member 12, in common with the other valves 11 anddisconnecting devices 13, 14. Owing to this collapsible container 15disposed within the bellows l, a supply of oxygen (constant quantity) isobtained which is allowed to vary in volume or capacity according to thediving depth. This is attained by causing the normal gas supply tobellows 1 from the base or station through conduits 3, 4 to be regulatedin accordance with the actual depth level of the diver. Thus, the oxygencontained in the collapsible container 15 will regulate the quantity ofbreathing gas which, during normal gas supply, can fill the spacebetween the wall of the bellows 1 and the external surface of thecollapsible container 15.

When diving to a depth of 230 meters, the oxygen volume will have to be0.8 liter to correspond to an oxygen concentration of 8 percent. At adepth of 30 meters, the oxygen will expand so as to occupy 5 liters ofthe total capacity of the bellows 1, which corresponds to the maximatedoxygen concentration for this depth.

The construction and function of the emergency breathing unit wouldappear still more clearly from the basic diagram shown in FIG. 4. Inthis case, the tripping member is shown in the form of a pivoting handle12 which is disposed within convenient reach for the diver on hisbreathing gas equipment. The pivoting handle is adapted to actuate alever having one portion extending down to the disconnectors 13, 14.Each disconnector 13 and 14, respectively, comprises an emergencyinterrupter and 21, respectively, and a pair of oppositely connectednon-return valves 18, 19 to prevent water ingress into the twointerrupted conduit portions.

The other end of the lever actuated by the pivotable handle 12 isconnected to a multi-functional valve device 23 adapted, in response toan actuation of handle 12 from its normal position shown for supplyingbreathing gas from the external gas supply system through conduits 3, 4,to disconnect the communication with these conduits 3,4 and to connectthe inhalation and exhalation conduits 7 and 8, respectively, into aclosed circuit including the gas purifier 9, and to open thecommunication between the auxiliary source of gas 5 and bellows 1. Thus,upon actuation of handle 12, the

diver will get completely released from the external supply of breathinggas and will be self-sustained from bellows 1.

As would appear quite clearly from the description hereinbefore, theemergency breathing units illustrated in the drawings should only beconsidered as suitable embodiments of the invention, the same, ofcourse, being susceptible of various modifications without departingfrom the scope of the invention.

We claim:

1. Breathing apparatus for deep diving, comprising:

a divers helmet,

an external breathing gas supply means,

inhalation and exhalationconduits each connected to said helmet;

quick release connecting means normally connecting said inhalationconduit and a feed conduit of said external gas supply means andnormally connecting said exhalation conduit and a return conduit of saidexternal gas supply system,

a gas storage means, I

a first branch conduit connecting said storage means and said inhalationconduit,

a second branch conduit comprising a first, normally closed valveconnecting said storage and said exhalation conduit,

an auxiliary gas source,

conduit means comprising a second, normally closed valve for connectingsaid gas source and said storage,

and manually operated means for simultaneously opening said first andsaid second valve and disconnecting said quick release connecting meansfor completely releasing the unit comprising helmet, storage andauxiliary gas source from the external gas supply system.

2. Apparatus according to claim 1 including a gas purifier inserted insaid second branch conduit.

3. Apparatus according to claim 1 wherein said storage means is abellows.

4. Apparatus according to claim 2, wherein the auxiliary gas source isin the form of a collapsable container disposed within the interior ofsaid bellows.

5. Apparatus according to claim 1, wherein said quick release connectingmeans are provided with two oppositely interconnected non-return valveswhich are adapted to be actuated in response to an emergencydisconnection so as to prevent wateringress into the external gas supplysystem and into the inhalation and exhalation conduits, respectively.

6. Apparatus according to claim 1 wherein the manually operated means isarranged, by means of a lever thereof, to actuate said quick releaseconnecting means and a multi-functional valve adapted, firstly to changeor switch over the connection of the inhalation and exhalation conduits,respectively from the external gas supply system to the auxiliary gassupply circuit, secondly to open said second branch conduit, and,thirdly, to open the conduit between the auxiliary gas source and thestorage.

7. Apparatus according to claim ll wherein the auxiliary gas sourcecontains a gaseous mixture of a pressure and a composition such as tocause the average oxygen partial pressure of the gas supplied to thediver to be 1.5 atm. abs., this average oxygen partial pressure beingexceeded for a brief initial period of time only, whereas the maximumoxygen partial pressure is 2.0 atm. abs., and the initial period of timeis one third of the total period of use.

1. Breathing apparatus for deep diving, comprising: a diver''s helmet,an external breathing gas supply means, inhalation and exhalationconduits each connected to said helmet; quick release connecting meansnormally connecting said inhalation conduit and a feed conduit of saidexternal gas supply means and normally connecting said exhalationconduit and a return conduit of said external gas supply system, a gasstorage means, a first branch conduit connecting said storage means andsaid inhalation conduit, a second branch conduit comprising a first,normally closed valve connecting said storage and said exhalationconduit, an auxiliary gas source, conduit means comprising a second,normally closed valve for connecting said gas source and said storage,and manually operated means for simultaneously opening said first andsaid second valve and disconnecting said quick release connecting meansfor completely releasing the unit comprising helmet, storage andauxiliary gas source from the external gas supply system.
 2. Apparatusaccording to claim 1 including a gas purifier inserted in said secondbranch conduit.
 3. Apparatus according to claim 1 wherein said storagemeans is a bellows.
 4. Apparatus according to claim 2, wherein theauxiliary gas source is in the form of a collapsable container disposedwithin the interior of said bellows.
 5. Apparatus according to claim 1,wherein said quick release connecting means are provided with twooppositely interconnected non-return valves which are adapted to beactuated in response to an emergency disconnection so as to preventwateringress into the external gas supply system and into the inhalationand exhalation conduits, respectively.
 6. Apparatus according to claim 1wherein the manually operated means is arranged, by means of a leverthereof, to actuate said quick release connecting means and amulti-functional valve adapted, firstly to change or switch over theconnection of the inhalation and exhalation conduits, respectively fromthe external gas supply system to the auxiliary gas supply circuit,secondly to open said second branch conduit, and, thirdly, to open theconduit between the auxiliary gas source and the storage.
 7. Apparatusaccording to claim 1 wherein the auxiliary gas source contains a gaseousmixture of a pressure and a composition such as to cause the averageoxygen partial pressure of the gas supplied to the diver to be 1.5 atm.abs., this average oxygen partial pressure being exceeded for a briefinitial period of time only, whereas the maximum oxygen partial pressureis 2.0 atm. abs., and the initial period of time is one third of thetotal period of use.